This program is pretty slow. Thanks to the caching, repeated visits from the same address will only result in one lookup. Therefore large files will be processed proportionally faster than small ones. The load from this program is very light, because it spends most of its time waiting for the resolver. This also means that large files can take quite some time to process. The solution is to split the log file and run several resolution processes in parallel. This is done by the script splitwr: splitwr logfile > logfile.resolved webalizer logfile.resolved rm logfile.resolved By default, splitwr runs 20 parallel resolution processes. The number can be changed by editing the script. WWW: http://siag.nu/webresolve/